Nondiffusing couplers for color photography



Patented Aug. 12, 1947 NONDI'FFUS ING COUPLER'S' FOR COLOR" PHOTOGRAPHY Abraham Bavley; Bi'nghamton, N. Y., assignor to General Aniline '& FilmCorporation, New York,

N. Y., a-corporationof Delaware No Drawing. Application May 20, 1944,- Serial No. 536,601

2 Claims.

This invention relates to color photography and is particularly concerned Witha process of colorphotography and photographic color forming; or

coupling compounds which are non-diffusing when incorporated in photosensitive gelatin emulsion layers.

The present invention relates to the photo-- graphic color process inwhich a color photographic image is producedby meansof 'acoupling reaction between a photographic developer and an intermediate or coupling compound, as-' has been described in PatentsNo. 1,055,155 and No. 1,102,028 to Fischer. In one method of" carrying out a color forming of this type the coupling compound is incorporatedjin the sensitive emulsion layer prior to coating it on the support, When this is done it is highly desirable that the coupling compound'should not Wander or diffuse from the layer in which it is incorporated, particularly when two or more layers are superimposed and are differentially sensitive, as such dif fusion of a coupling component causes inaccurate color rendition. It is also important that the coupling compound which is incorporated in the sensitive layer should not desensitize or otherwise adversely affect the sensitive .emulsion'layer;

It is therefore an object of this invention to provide a photographic color forming or couplingcompound which may be incorporated in a sensitive emulsion without any adverse effect on such emulsion and which when so incorporated isnon-difiusible therein. Other and further objects Will beapparent as the -description progresses.

I have foundthat known-colorcoupling com= pounds which contain an acidic radical, either'a sulfonic acid substituent or ascarboxyl group;"may be rendered non-diiiusin without. any "adverse effect on the tendency of the coupling compound to desensitize or otherwise adversely affect the sensitive emulsion by reacting such .color cou-. pling compounds-with a long chain amine, in order .to forrn an amine salt. of the color former and employing the thus obtained amine salt as a color forming or coupling component which is incorporated in a photographic emulsion.

As the coupling component I may employ any known coupling component which contains an acidic substituent'. As is well known, the coupling components ordinarily employed in color forming development are compounds which contain an active methylene group. In general aceto-acetic acid ester and its derivatives are employedfor'the production of yellow and green dye images, for the blue-reds, or magentas it is customary'to employ a'pyrazolone, and Various phenols and 'n'aphthols are employed for the'productiorr'of lolue dye images: Manyofthese known coupling components contain sulfonic acid or carboxylic acid-substituen'ts and'these may readilywbe reacted with along chain' aliphatic amine in order to-produce the corresponding amine salt which is non diffusing.

A s} known color' forming orcoupling com-ponents W-hich contain an acidic-group, and which; therefore; are suitable for use in practicing the present invention,- may be named, for example; .p-ketonicacid esters ofth'e following typef Q0 0 onto ONHR and.

in which X stands foria sulfonic or carboxylic acid group and R is alkyl, aryl or aralkyl. Specific exampes ofisuch esters are benzo-ylaceta'nilide-p-sulfonic acid and naphthoyl-Z-acetanilide; 5-sulfonic acid; These compounds=are suitable for the production-oi yellow images, For the pro duction of red or magenta images, pyrazolones which containa sulfonic orcarboxylic acid group 3 may be employed. Thus, pyrazolones of the following type:

t t=o V in which X stands for a sulfonic or carboxylic acid group and Y stands for hydrogen or a sulfonic or carboxylic acid group, and R is alkyl, aryl or aralkyl, are suitable for use in practicing the present invention. Typical specific examples of compounds of this type are:- 1-(3'-sulfophenyl) -3-methyl 5 pyrazolone; 1- (5'-sulfophenyl) -3-methyl-5-pyrazolone. For the production of blue colors, phenols and naphthols, con taining a sulfonic or carboxylic acid group, may

be employed. The fOllOWil'ig types of compounds are suitable: P I I and in which X stands for sulfonic or carboxylic acid group and R is alkyl, aryl or aralkyl. Specific examples of such compounds are: e-hydroxy naphthoyl aminobenzene-ii-sulfonic acid; an a-hydroxy naphthoyl aminonaphthalene-6-sulfonic acid.

The amines which I react with these color coupling compounds in order to produc the amine salt which is non-diffusing are preferably primary ing amine salt compound C infifquati on i belowf Eq. I.

HaC(HJ-CHz HaC-C= ''*|CH2 V This amine salt may readily be incorporated in a conventional gelatino silver halide photosensi tive emulsion and when so incorporated is nondiffusin and is Without adverse effect on the emulsion.

7 Other known pyrazolones, such as those mentioned previously in this specification, which contain a sulfonic acid or carboxylic acid group, may

be substituted for the l-p-sulf0nic-phenyl-3- methyl pyrazolone mentioned above and reacted with an alkyl amine in order to produce the corj responding amine salt which may readily be incorporated in a sensitive photographic emulsion in the usual manner.

aliphatic amines containing at least 8 carbon 7 The thus obtained amine salt was incorporated. in a conventional gelatino silver halide photographic emulsion in the usual way by dissolving a small amount of this amine salt, about 8 grams, in 3 cc. of sodium hydroxide of 40 percent strength, 25 cc. of methanol, and 70 cc. of water and this solution was then added to 500 cc. of a gelatin silver halide emulsion of 5 percent strength. When so incorporated in a photographic emulsion, the amine salt exertedno. adverse effect on the emulsion and was non-difiusing therein. The thus obtained emulsion was cast on a film support, in accordance with conven- .tional practice, and the film exposed. By developing with 'a color forming developer, for in-.

stance, p-diethylaminoaniline, a magenta picture was obtained.

Example 2 A typical known color forming compound containing a sulfonic acid group which is a derivative of aceto-acetic acid ester is benzoyl acetani lide-p-sulfonic acid. This was readily reacted with an aliphatic amine, for instance, octadecyl amine, in order to produce the corresponding; amine salt F, as illustrated in Equation II belowz:

The present invention will be readily unders 1 stood from the following specific examples which are given only for the purpose of illustrating the present invention and it should be understood that the invention is in no way limited to these examples.

Example 1 Atypical example of a known color forming pyrazolone containing a sulfonic acid orcarboxylic acid group is l-p-sulfonic pheny1-3- methyl pyrazolone. This compound may readily be reacted with an amine, for instance, hexadecylamine, in order to produce thecorrespond- 0113 0112) nNHaSOg-O-NHC 0 03,0 00..

This amine salt F may readily be incorporated in: a photographic sensitive emulsion and the emul sion cast on a photographic film support, in tha same manner as in Example 1, and when spin-- corporated therein is without adverse effect om the emulsion and when so incorporated'is nondifiusing therein. By developing with a color; forming developer, a yellow picture is obtainedi.

Other derivatives of aceto-acetic acid ester which contain "an acidic group and which are: known to have color forming properties, for instance those of the type heretofore mentioned, may be treated in a like manner and non-difius.

ing amine salts, which are suitable for use as nondifiusing color compounds, are thus obtained.

Example 3 A known naphthol color forming or coupling compound for the production of blue pictures is a-naphthoylaminocyclohexane-4-sulfonic a 0 id. This may be reacted with a primary amine, for instance, octadecylamine, as illustrated in Equation III, to produce the corresponding amine salt I.

Eq. III.

1 fi-C ONHCtHn NH;(CH2)17CH3 W H SOaH C ONHCaHu SOzNHa( H:)11 a This amine salt may readily be incorporated in a photographic emulsion as a coupling compound, in the same manner as in Example 1, and when so incorporated exerts no adverse efiect on the emulsion and is non-diffusing therein. By developing with a color forming developer, a blue picture is obtained.

Other known phenols and naphthols which are color coupling compounds and which contain an acidic group, for instance, those mentioned above, may be treated in a like manner to produce the corresponding amine salt and the amine salt used as a non-diffusing coupling compound.

It should be noted that the amine salts of naphthols and phenols Which contain a, sulfonic acid group in the para-position, with respect to the hydroxyl group, are particularly advantageous for use as non-diffusing coupling compounds. Many of the dyes obtained by coupling a naphthol or phenol with a photographic color developer, for instance, an aryl amine or diamine, are quite insoluble with the result that on color forming development clumping of the dye occurs. This is particularly true if the naphthol or amine coupling compound has been treated in order to render it non-diffusing by methods heretofore known in the art. As is well known in the art of color forming development, coupling between a naphthol or phenol coupling compound and the aryl amine employed as the developing agent takes place at the para-position with respect to 6 the hydroxyl group. In accordance with the present invention, this coupling results in the sulfonic acid or carboxylic acid group being split ofi as illustrated in Equation IV below:

Eq. IV.

O ONHCoHn C ONHCuHu I i HaC(CH2)nSOaH N 1130 \OHB This resulting dye is sufliciently soluble in the emulsion layer that clumping does not occur. On the other hand, the coupling component is sufficiently non-diffusible prior to color forming development and the resulting coupling that it does not diffuse from the sensitive emulsion in which it has been incorporated.

I claim:

1. A photographic silver halide emulsion containing a color former fast to diffusion, said color former comprising the salt of a primary aliphatic amine containing at least 8 carbon atoms and a color former selected from the class consisting of phenols and naphthols having an acidic group selected from the class consisting of carboxylic and sulfonic acid groups in para-position.

2. A photographic silver halide emulsion containing a color former fast to diffusion, said color former comprising the salt of a primary aliphatic amine containing at least 8 carbon atoms and a color former selected from the class consisting of phenols and naphthols having a sulfonic acid group in para-position.

ABRAHAM BAVLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

